1. Field of the Invention
The present invention relates to an ophthalmologic measurement apparatus or the like for measuring an eye to be inspected.
2. Description of the Related Art
As for an ophthalmologic measurement apparatus for measuring an eye to be inspected, two types are known: a stationary type; and a hand-held type.
An ophthalmologic measurement apparatus of the stationary type includes a stand for putting a main part of the apparatus on an installation surface, a base configured to be slidable on the stand in back-and-forth and right-and-left directions, a measurement unit connected to the base and including various kinds of optical systems and an imaging system, a jaw receiving stand/forehead support for positioning a jaw or a forehead of a person to be inspected, and the like. In the stationary-type ophthalmologic measurement apparatus, the base is slid to the right or left mainly to switch an eye to be inspected of a person between his/her right and left eyes. Thus in the stationary-type ophthalmologic measurement apparatus, it is possible to recognize which one of right and left eyes is to be inspected by detecting whether the measurement unit is located on the right or left side with respect to the center of the stand.
On the other hand, the hand-held type ophthalmologic measurement apparatus has neither a stand nor a base, and thus it may be difficult to recognize which one of right and left eyes is to be inspected in the same manner as the stationary-type ophthalmologic measurement apparatus. To handle the above situation, Japanese Patent Laid-Open NO. 7-246188 discloses ophthalmologic equipment configured to have a shielding plate movable between a position where to shield a right eye a position where to shield a left eye, and also have a switch disposed in the inside of the main part of the equipment to allow it to recognize which one of right and left eyes is to be inspected.
On the other hand, Japanese Patent Laid-Open No. 8-256984 discloses an eye examination apparatus having a function of detecting whether an eye of interest is a right or left eye. This eye examination apparatus has two illumination units that provide illumination light from both sides of an eye examination unit, and a photosensor unit disposed between the two illumination units and configured to sense two light rays that are originally emitted from the two illumination units and reflected from a face of a person to be inspected. The photosensor unit detects a light intensity for each reflected light ray and determines, based on the detected light intensity of each reflected light ray, whether the eye to be inspected is a right or left eye.
In conventional ophthalmologic measurement apparatuses, including those disclosed in Japanese Patent Laid-Open Nos. 7-246188 and 8-256984 described above, although it is possible to recognize which one of right and left eyes is to be inspected, an eyepiece part (a so-called eyecup) has the same shape regardless of whether a right or left eye is to be inspected, and thus it is difficult to achieve a good contact between the eyepiece part and a face of a person to be inspected. More specifically, a positional relationship between a part from an inner eye corner to a nose and a part from an outer eye corner to an ear is opposite between right and left eyes. In general, the length between an eye (inner corner) and a nose is shorter than the length between an eye (outer corner) and an ear. Besides, there is a difference in an angle of a face with respect to a straight-ahead eye direction. Therefore, for example, when an eyepiece part has a shape that allows the eyepiece part to be in good contact with an area around left eye, if it is tried to directly put this eyepiece part into contact with an area around right eye, a fitting error in size and/or angle may occur.